MRI误诊的椎体海绵状血管瘤18F-FDG PET/CT显像一例

笔者报道了一例双下肢乏力4月余,加重伴疼痛、活动受限一周的病例。MRI显示病灶累及胸3椎体、椎体附件和周围组织,并延伸到椎管内硬脊膜,增强后病变明显强化,MRI因病变范围广且增强后明显强化,考虑为恶性肿瘤。而18F-FDG PET低代谢结合CT点状、栅栏状钙化灶和椎体骨质无破坏,考虑为海绵状血管瘤;且术后病理因病灶内见异常血管聚集成丛状,血管腔内有大量红细胞,诊断为海绵状血管瘤。文献复习加深了对椎体海绵状血管瘤的认识,其可累及椎体、椎体附件,甚至延伸到椎管内和（或）周围组织。海绵状血管瘤是一种血管畸形,MRI增强后呈明显强化,但是PET显像则呈低代谢。当MRI显示病变范围广伴明显强化,而椎体无骨质破坏,怀疑恶性肿瘤时,应结合PET/CT对诸如海绵状血管瘤等良性病变进行鉴别诊断。     

Diagnosis of prosthetic joint infection at the hip using the standard uptake value of three-phase 99mTc-hydroxymethylene diphosphonate SPECT/CT

Annals of Nuclear Medicine - To retrospectively investigate whether the standard uptake value (SUV) of 99mTc-bone single-photon emission computed tomography (SPECT)/CT could be useful for...     

Increased uptake in a vertebral bone island seen only on SPECT

Skeletal scintigraphy may be performed to evaluate a suspected bone island. In general, a bone island does not demonstrate increased uptake on bone scan. A case of increased uptake in a lumbar vertebral body bone island seen on SPECT, but not conventional planar imaging, is presented.     

Acute intervertebral gas following vertebral fracture: CT demonstration

The occurrence of intervertebral gas secondary to the vacuum phenomenon has been previously described and is thought to be pathognomonic of degenerative disk disease. The case reported here illustrates that the intervertebral vacuum phenomenon may occur following trauma, suggesting that it is not exclusive to degenerative disk disease.     

Focal myocardial uptake in a patient with carcinoid tumor by indium-111-pentetreotide on SPECT/CT

We present a case of a 44 year old man with flushing, diarrhea and markedly elevated 24 hour urinary 5-HIAA level, who was referred for an indium-111 pentetreotide study, after the excision of a carcinoid tumor in the terminal ileum. Scan findings revealed focal uptake in the myocardium and liver, suspicious for metastases. Subsequent transthoracic echocardiogram failed to demonstrate a cardiac lesion. Previously, our group has unequivocally demonstrated the usefulness of software fusion of SPECT and CT imaging in the evaluation of a carcinoid metastasizing to the myocardium. This case illustrates that hardware SPECT/CT fusion imaging utilizing indium-111 pentetreotide to evaluate metastatic carcinoid tumors can be useful. In addition, the echocardiogram can yield false negative results, because of a smaller lesion size and the influence of an operator-dependent factor.     

Lymphoscintigraphy for sentinel node mapping using a hybrid SPECT/CT system.

Lymphoscintigraphy is performed before sentinel node (SN) biopsy for SN mapping. It is of clinical importance mainly if the tumor is located in body parts with ambiguous lymph node drainage. The purpose of this study was to assess the clinical benefit of fused SPECT/CT images to planar images for SN mapping. METHODS: Thirty-four consecutive patients with cutaneous malignant melanoma (n = 28) and squamous cell carcinoma (n = 6) and scheduled for SN biopsy were enrolled. Primary tumors were located in the trunk (n = 12), in the extremities (n = 12), in the head and neck (n = 9), and in the penis (n = 1). Scintigraphy was performed using a hybrid gamma-camera/low-dose CT system. Planar images and fused SPECT/CT images were interpreted separately. RESULTS: SPECT/CT identified multiple draining basins in 6 of 12 patients (50%) with trunk melanoma and in 3 of 9 patients (33%) with head and neck melanoma or mucosal tumor. In 9 of 21 patients (43%) with a primary tumor located in the head and neck or trunk region, SPECT/CT-fused images identified SNs that were missed on planar images, 2 of which were involved with tumor. Three of the 9 nodes were located close to the injection site and were hidden by its scattered radiation, and 2 were in-transit nodes. Another 4 nodes, identified on fused images only, were located in an additional basin to those identified on planar images. Fused images were of no added value either in patients with limb melanoma or in a patient with a penile melanoma. CONCLUSION: SPECT/CT SN mapping provides additional data that are of clinical relevance to SN biopsy in patients with trunk or head and neck melanoma and in patients with mucosal head and neck tumor.     

Anatomical accuracy of hybrid SPECT/spiral CT in the lower spine

AIM: The anatomical accuracy of hardware-based registration of skeletal single photon emission computed tomography (SPECT) and X-ray computerized tomography (CT) has as yet not been studied. The aim of this study was to evaluate this variable in the lower spine for a newly introduced hybrid SPECT/spiral-CT camera. METHODS: In 22 patients referred for degenerative joint disease or tumours, whole-body bone scintigraphy including hybrid SPECT/spiral CT of the lower spine was performed. Subsequent analyses were performed on these pairs of images as well as on data sets obtained after using a rigid automated fusion procedure in addition. Two observers independently measured the distances between the visually determined centres of gravity of the CT and SPECT representation of the fourth and fifth lumbar vertebral body in the X-, Y- and Z-directions (X-, Y- and Z-distances). RESULTS: The distances determined by the two observers for the two vertebral bodies correlated significantly and were averaged for further analysis. For hybrid SPECT/spiral CT without consecutive automated registration, the mean X-, Y- and Z-distances were 1.6+/-1.9 mm, 1.7+/-1.3 mm and 0.9+/-0.5 mm, respectively. Additional automated registration lowered these values to 1.2+/-0.9 mm, 1.1+/-0.7 mm and 0.8+/-0.4 mm, respectively. The difference for the Y-distance proved statistically significant (P<0.05). Additional automated registration significantly reduced the number of subjects in whom at least one of the distances determined was greater than the SPECT pixel size of 4.6 mm from 14% (n=3) to 0% (P<0.05). CONCLUSION: Hardware-based fusion between skeletal SPECT and CT offers a nearly perfect data match in the lower spine. The additional use of a tool for automated rigid registration has the potential to reduce the error of alignment even further and may be useful in patients with reduced compliance leading to movements between the two examinations.     

SPECT/Spiral-CT hybrid imaging in unclear foci of increased bone metabolism: a case report

In bone scintigraphy, the differentiation between degenerative processes and bone metastases is still difficult. Therefore, additional radiological studies are regularly needed after bone scintigraphy. The now introduced hybrid-cameras combining single-photon emission computed tomography (SPECT) and spiral-CT are unique in the sense that they offer the opportunity to correlate the functional information with morphology in one session. We herein present two patients in whom this technological setup allowed a definite diagnosis in scintigraphically unclear vertebral lesions. In a patient with breast cancer, hypermetabolic lesions were clearly correlated with osteolyses. In another patient with synovial carcinoma, spondylosis and spondylarthrosis caused focal tracer uptake in the lumbar spine. In addition to an improved diagnostic accuracy, SPECT/Spiral-CT will considerably abbreviate the diagnostic process.     

增殖性脑血管病^99Tc^m-ECD SPECT/CT显像一例

患者女,62岁,因言语不清伴右眼视物不清3 d就诊。血常规、肝肾功能及凝血全套检测均正常。体格检查:血压155/71 mmHg(1 mmHg=0.133 kPa),神清,格拉斯哥昏迷评分(Glasgow coma scale,GCS)15分,定向力正常,口齿不清;双侧瞳孔直径3.0 mm,光反应灵敏,两侧眼球活动无异常,粗测视野右侧同向偏盲;两侧额纹对称,两侧鼻唇沟基本对称,伸舌居中;右下肢可疑5级-,余肢体肌力5级,两侧肌张力无异常,两侧腱反射对称阳性,巴宾斯基征阴性。患者既往无高血压、冠状动脉硬化性心脏病及糖尿病史。头部CT检查示左枕叶低密度,诊断为脑梗死。     

Idiopathic hepatic uptake of (99m)Tc methylene diphosphonate: a case report

OBJECTIVE: Two sequential (99m)Tc methylene diphosphonate (MDP) scans were performed on a 42-y-old woman with insulin-dependent diabetes mellitus, chronic right pyelonephritis and anemia. The initial scan showed reduced skeletal uptake with intense and diffuse hepatic uptake. Because these findings were similar to those seen when excessive hydrolyzed-reduced (99m)Tc colloids are present in the radiopharmaceutical, the scan was repeated after an adequate time delay. Increased skeletal uptake was evident in the second scan, but the hepatic uptake persisted. Although there are numerous causes of soft tissue activity on (99m)Tc MDP bone scans, the responsible pathologic entity is not always clear. This study reviews several possible reasons for such uptake, although the exact mechanism in this case remains conjectural.     

Use of lymphoscintigraphy with SPECT/CT for sentinel node localization in a case of vaginal melanoma

A 45-year-old woman with vaginal melanoma underwent Tc-99m sulfur colloid (filtered) lymphoscintigraphy with the acquisition of planar and SPECT/CT images for localization of a sentinel node before surgery. The study identified both inguinal and perirectal sentinel nodes, which proved beneficial in mapping potential anatomic spread of disease for staging and therapy planning. These results provide evidence for the use of routine SPECT/CT imaging for pelvic lymphoscintigraphic studies or as an adjunct tool for localizing sentinel nodes in cases that would not be demonstrated with planar imaging alone.     

Lymphoscintigraphy in early-stage non-small cell lung cancer with technetium-99m nanocolloids and hybrid SPECT/CT: a pilot project

Objective

The goal of our study was to determine if lymph node activity could be visualized using a hybrid single-photon emission computed tomography/computed tomography (SPECT/CT) scanner with two commonly used colloidal lymphatic radiotracers—^99mTc-antimony sulfide colloid (ASC) and ^99mTc-filtered sulfur colloid (FSC) in the setting of low-stage non-small cell lung cancer (NSCLC).

Methods

Patients undergoing CT-guided percutaneous lung biopsies for clinically suspected early-stage lung cancer were randomized to peri-lesional injection of 37 MBq (0.5 mL) of either ASC or FSC. SPECT/CT of the thorax was performed at either 1, 2, or 3 h post-injection. The images were reviewed to determine if lymph node activity separate from the injection site could be identified.

Results

24 patients were included. Lymph node activity was identified in 50 % of patients. A total of 15 lymph nodes with activity were visualized including 5 ipsilateral hilar, 6 ipsilateral mediastinal, and 4 distant locations. No contralateral mediastinal or hilar activity was visualized. There was a tendency to improved visualization with ASC and the longer 3 h wait time. Most patients also demonstrated significant pleural, tracheobronchial, and/or systemic activity.

Conclusions

SPECT/CT imaging can demonstrate lymph node activity separate from the injection site in at least some low-stage NSCLC patients with a perilesional injection of ^99mTc nanocolloid tracers. Further investigation into the role of pre-operative lymphoscintigraphy with SPECT/CT in patients with lung cancer is warranted.     

Small-animal SPECT and SPECT/CT: application in cardiovascular research

Preclinical cardiovascular research using noninvasive radionuclide and hybrid imaging systems has been extensively developed in recent years. Single photon emission computed tomography (SPECT) is based on the molecular tracer principle and is an established tool in noninvasive imaging. SPECT uses gamma cameras and collimators to form projection data that are used to estimate (dynamic) 3-D tracer distributions in vivo. Recent developments in multipinhole collimation and advanced image reconstruction have led to sub-millimetre and sub-half-millimetre resolution SPECT in rats and mice, respectively. In this article we review applications of microSPECT in cardiovascular research in which information about the function and pathology of the myocardium, vessels and neurons is obtained. We give examples on how diagnostic tracers, new therapeutic interventions, pre- and postcardiovascular event prognosis, and functional and pathophysiological heart conditions can be explored by microSPECT, using small-animal models of cardiovascular disease.